In recent times, satellite systems, known as "dishes", have become increasingly popular. These satellite reception systems enable the owner to view a wide variety of television signals which are broadcast from the earth up to repeater satellites and then back down to the earth. The electronics associated with these reception dishes have become increasingly more sophisticated and more powerful so that at the present state of the art a dish merely four feet in diameter can "pull in" adequately strong signals from certain satellites which are acceptable for home TV viewing.
Multiple TV sets in a single location served by a single dish are also becoming increasingly more popular. This can be found in hotels where many room TVs, up to hundreds and even thousands, can be served by a single satellite dish, as well as in homes where two television sets are to be connected to a single dish. As many as four, five or even six television sets in one home are fairly common.
Another recently developed phenomenon in television entertainment is the use of the video cassette recorder (VCR) for home use. In a home having several television sets, it would be desirable to direct the VCR signal to any one or to several of the television sets in the home. At present, the common arrangement is to have the VCR more or less permanently wired to one of the home television sets.
Cable television is another option available to homes, hotels and the like wherein a large number of signals of very high quality are delivered on an underground cable from a central supplier to the cable subscribers. Here again, in multiple TV installations, it would be highly desirable if the user could direct the cable signal to any one or to several of the television sets in the multiple television set installation.
Another application with which the invention is involved is the use of television cameras and receivers for alarm and surveillance purposes. This is often done in department stores, factories, hotels, and to an increasing extent, also in the home. The integration of such surveillance, alarm and the like systems into the regular TV intended for entertainment purposes, at the present time, is either rudimentary or non-existent. That is, separate television receivers are usually provided for alarm and entertainment purposes.
Another aspect of the prior art in regard to satellite television is that the satellite signals are broadcast back to earth at an extremely high frequency, on the order of 4 to 12 gigahertz (GHz), and the frequency range at the television set itself is on the order of 100 MHz. This high frequency signal must be converted down to the standard television UHF frequencies to which the various channels of the television are pre-tuned. Accomplishing this with reasonably priced electronics suitable for the home market has been a problem in the prior art, and is solved in a unique manner by the present invention. The signal is demodulated, amplified and delivered to the television in the form of a clear sharp TV picture with good sound by the invention system, which is itself produced at a reasonable cost.
Another growing consumer product is the home video camera. Here again, the invention's integrated system will permit showing of home video made by such cameras on any one or any combination of the plurality of television sets served by the invention hybrid system.
Most satellite systems commercially available operate by extracting a single signal from a broad band of different signals received at the dish from the satellite. This naturally results in a system wherein a single television only can be provided with a single signal only at any one time. This is a severe disadvantage in that the costs are multiplied if several signals are desired to be used simultaneously.